Heater element for embedment in a mastic slab



Dec, 18, 1962 F. w. JAMISON HEATER ELEMENT FOR EMBEDDMENT IN A MASTICSLAB Filed Oct. 7. 1960 2 Sheets-Sheet 1 FIG.2

INVENTOR, FREDERICK W. J

FlG A. BY 9 gg gj ATTORNEY Dec. 18, 1962 F. w. JAMISON 3,069,522

HEATER ELEMENT FOR EMBEDDMENT IN A MASTIC SLAB Filed Oct. '7, 1960 7 P 2Sheets-Sheet 2 FlG.7

IN V EN TOR.

' FREDERICK w. JAMISON gwkcgh ATTORNEY United States Patent ()fifice3,%;9,5ZZ Patented Dec. 18, 1962 sneasza TER ELEMENT FUR EMEEBE'EENT ENA MASTEQ SLAB Frederick W. Jamison, Garden City, Monroeviiie, Pa. (11%Coigate Drive, Pitcairn, Pa.) Fitted Get. '7, 19643, Ser. No. 61,298 1Ciainr. (1. 21.9-4 .9)

This invention relates to a method and apparatus for producing heatedsurfaces primarily for the purpose of maintaining such surfaces free ofice and snow accumulation and with the surfaces being primarily of thetype that constitutes steps, driveways and walkways although, notrestricted to any specific use.

Basically, the invention contemplates the formation of a heater elementembodying a predetermined length of Wire that is bent upon itself toform a plurality of equidistantly spaced flights that are supported andanchored against movement with respect to each other so that th entireassembly may be disposed as a heat producing element and that may bedisposed in molded relation to a panel of cementitious material or, maybe bodily placed upon a previously formed concrete surface, such as adriveway ribbon and then covered and bonded to the surface of theconcrete by the application of the well known epoxy resin.

The invention readily lends itself to prefabricated structures, such asthe conventional concrete panel or the heater element may be embodiedwithin the concrete at the point of use. Basically, the inventionproposes a heater element that is prefabricated into a relatively rigidgrill having the terminal ends of the wires projecting from the tubes tobe jointly soldered into a self-connecting connector device or, thewires may be extended outwardly for assembling the device in parallelwith respect to a source of electrical energy.

Novel features of construction and operation of the device will be moreclearly apparent during the course of the following description,reference being bad to the accompanying drawings wherein has beenillustrated the preferred forms of the device and wherein likecharacters of reference are employed to denote like parts throughout theseveral figures.

in the drawings:

FEGURE 1 is a perspective view of a heater element constructed inaccordance with the invention,

FIGURE 2 is a transverse section taken on line 2--2 of FIGURE 1,

FIGURE 3 is a fragmentary perspective view of a modified method ofassembly of the heater element,

FIGURE 4 is an enlarged transverse sectional view taken through acompleted panel of mastic composition having the invention embodiedtherein,

FIGURE 5 is a diagrammatic view illustrating the use of the heaterelements in the formation of steps.

FIGURE 6 is a diagrammatic illustration showing a pair of heaterelements that are disposed in end to end relation and forming acontinuous heated surface for a driveway and,

FiGURE 7 is a diagrammatic illustration showing at least two heaterelements arranged in parallel relation for forming a heated walkway.

Referring specifically to the drawings, the numeral 5 designates a pairof spaced apart parallel and preferably plastic separators that areapertured at equidistantly spaced points throughout their length asindicated at 6 for the snug reception of plastic tubes 7. The tubes 7extend a relatively short distance beyond the outer faces of the strips5, as clearly shown. The tubes 7 constitute the guiding and threadingmeans for electrical conductors 8. The conductor 8 of one unit, asillustrated in FIG URE 1 is initially threaded through an outermost tube7,

bent upon itself at the opposite end of the tube and guided by anysuitable form to constitute a loop 9 and then threaded through the nextadjacent tube 7, where it is again directed over a suitable form orguide to form a second loop 9 at the opposite end of the device. Thisthreading of the conductor 8 through the tube 7 will be apparent, sinceit is certainly desirable that the conductor 8, being the source ofheat, must be continuous throughout the panel to be formed. Theconductor 8 may be of any desirable type of conductor commonly employedin heaters or the like and the tubes 7 constitute a very desirabie meansfor forming the unit and also for maintaining the several flights of theconductor 8' in the accurate spaced apart relation, such spacing beingdetermined by a size of panel or slab to be formed. In the form of theinvention illustrated in FIGURE 1, the free ends of the conductor 8 aresoldered or otherwise connected to a insulator type of self-threadingconnector 10, such as that illustrated in my co-pending applicationserial No. 20,916, filed April 8, 1960. The connector 10 however is ofwell known construction and has only been illustrated herein as beingone desirable means of connecting several panel devices in parallel fromthe single source of electrical energy. The spacer strips 5 may be ofany height and of course are dimensioned in accordance with the degreeof spacing required for the heater element with respect to itsparticular application either into a mastic sin or panel or when laiddirectly upon a concrete sidewalk and covered by a suitable resin, suchas epoxy.

In FIGURE 3, there has been illustrated a slightly modified form of thestructure of Fi'GURE 1, here including spacer strips Iii, formed ofplastic or any other nonconducting material and with one edge of thestrips 11 being notched as indicated at 12 to receive the plastic tubes13. The opening of the notch 12 is slightly smaller than the tubes 13,reauiring that the tubes be forced downwardly into the notches to havean interlocking engagement into the notches. The notches are of suchdepth that the tubes 13 will lie substantially flush with the upper edgeof the strips 11. In all other respects the assembly will besubstantially identical to that illustrated in FIG- URE 1.

In FIGURE 4, there has been illustrated a mastic panel or slab with theheater element embodied therein. While the heater element may bevertically spaced from the top and bottom surfaces of the slab 14, theslab may vary in thickness in accordance with a particular use and thestrips 5 or 11 may be disposed in the bottom of a metallic form or thelike and the mastic mass poured thereover or, if the slab is to berelatively thick, it may become necessary to support the strips 5 at apredetermined elevation in the form so that the heater element will liesubstantially close to the upper or trafiic surface of the slab.However, this is a matter of degree and may be varied in accordance withthe usage of the device. It may be desirable that the heater element Abe laid directly upon the exposed surface of a prebuilt concrete walk orthe like and in such case, the concrete is thoroughly cleaned beforeplacing the heater element thereon and then, with a suitable spray ortroweling method, the well known epoxy resin may then be appliedthereto, securely bonding the heater element to the old concrete surfaceand also encasing the heater element to a predetermined thickness abovethe concrete. In all cases, the conductor 8 is extended from the heaterelement in any desirable manner for connection to adjacent units eitherin series or in parallel.

in FIGURE 5, there has been illustrated a pair of heater elements A thatare disposed in parallel relation and proportioned to constitute eithermolded'steps or a heated cover for previously built masonry steps. Eachunit includes the strips 5, the tubes 7 and the conaces,

ductors 8. in the arrangement shown in FIGURE 5, conductors 8 of theunits A are contin one and tle positive and negative leads of theconductors are electrically connected to a source of electrical energy,thus establishing a continuous uninterrupted heater for the severalsteps.

FEGURE 6 illustrates the means for assembling a plu rality of the heaterunits A in end to end relation as when constituting a heated surface fordriveways or the like. While the r eater units A may be embedded intothe mastic of the driveway at the time of construction, they can also beapplied to the top of driveway ribbons of concrete that have beenpreviously formed and will be anchored or encased in epoxy res n.

In FZGURE 7, there has been illustrated of heater elements A that areadapted to be in a manner to constitute a can" ous walkway. the

ergy as illustrated, is preferably along one side of the d walkway andthe conductors having connection with the positive and negative sides ofthe source of electrical energy may be threaded in a continuous mannerthrough t e several tubes '7. in this pa icular arrangement i, iscontemplated that the heater units A. shall be embedded in the concreteforming the walk at the site of construction. It is also possible thatthe heater unit A be disposed upon a previously constructed sidewalk andbonded encased by the use of epoxy resin.

It will be apparent from the foregoing there has been provided a verysimple a d economical method of forming a unit to be en d ed into aconcrete panel or that also readily adapts itself to the application ofthe unit to a pre-bult concrete wall: or driveway by the use of the Wellknown epoxy resin. lhe use of the strips 5 and the tubes '7 present arelatively rigid unitary structure through whic. the wires 8 arethreaded with the unit adapted to be produced and sold to manufacturersof concrete slabs or to others for the application of a heater elementto the previously constructed tratfic bearing surfaces, such as thesidewalks, driveways or the like. While the unit A may be supported andmolded directly into a mastic panel such as that illustrated in r l URE4, it is also contemplated that the unit be disposed in overlyingrelation to a suitable insulating panel for retar mg the dissipation ofheat downwardly so that great mass of the heat will be directed towardthe surface of the panel where it functions to maintain the surface freeof ice and snow accumulation. The application the heater units to aninsulating board or insulating panel has been disclosed in myapplication above identified however, the device of this inventionprovides for its use either with or without an insulating support sinceadequate heat is generated and directed to the surface of the panelcapable of retzuding the accumulation of foreign elements. Also the d myi vention, w re to secure by Letters Patent i A heater element embe .tinto a mastic s that comprises a plura ity of relatively slender tubesof equal length, the tubes b ing connected adjacent their ends with specr in manner are held in equidistantly sgaced parallel relation with thefree ends of the tunes extending beyond the spacer strips. a cor.

to extend outwat a, the c the terminal ends of the conducsource ofelectrical energy, the said ti? being formed of a non-cor ctive mateupon their upper edge be points to receive the end p notches beingreduced at per edge of the strips to ermit the tubes to have a snappingengagement into the notches so that the tubes unon their upper Si'ZESSare flush with the upper ed s of the s the tubes being formed ofrelatively thin .rc having an inner diarne er capable tree Sli ..gmovement of the con ductor during the a sembly of the clen the saidcouductor when exten tube to the next for a My bent.

